text: The conservation equations for vertical momentum, heat and salinity equations (under Boussinesq's approximation) have the following form for double diffusive salt fingers:
  Where,  U and W are velocity components in horizontal (x axis) and vertical (z axis) direction; k is the unit vector in the Z-direction,  k is  molecular diffusivity of heat, k is  molecular diffusivity of salt, α is coefficient of thermal expansion at constant pressure and salinity and β is the haline contraction coefficient at constant pressure and temperature.
  The above set of conservation equations governing the two-dimensional finger-convection system is non-dimensionalised using the following scaling: the depth of the total layer height H is chosen as the characteristic length, velocity (U, W), salinity (S), temperature (T) and time (t) are non-dimensionalised as 
  Where, (T, S) and (T, S) are the temperature and concentration of the top and bottom layers respectively. On introducing the above non-dimensional variables, the above governing equations reduce to the following form:
  Where, R is the density stability ratio,  Ra is the thermal Rayleigh number, Pr is the Prandtl number, Le is the Lewis number which are defined as 
  Figure 1(a-d) shows the evolution of salt fingers in heat-salt system for different Rayleigh numbers at a fixed R. It can be noticed that thin and thick fingers form at different Ra. Fingers flux ratio, growth rate, kinetic energy, evolution pattern, finger width etc. are found to be the  function of Rayleigh numbers and R.Where, flux ratio is another important non-dimensional parameter. It is the ratio of heat and salinity fluxes, defined as,